The SSH daemon must be configured to not allow gateway ports.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-63213	ESXI-06-000022	SV-77703r1_rule		Low

Description
SSH TCP connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. This function can provide similar convenience to a Virtual Private Network (VPN) with the similar risk of providing a path to circumvent firewalls and network ACLs. Gateway ports allow remote forwarded ports to bind to non-loopback addresses on the server.

STIG	Date
VMware vSphere ESXi 6.0 Security Technical Implementation Guide	2019-01-04

Details

Check Text ( C-63947r1_chk )
To verify the GatewayPorts setting, run the following command: # grep -i "^GatewayPorts" /etc/ssh/sshd_config If there is no output or the output is not exactly "GatewayPorts no", this is a finding.

Fix Text (F-69131r1_fix)
To set the GatewayPorts setting, add or correct the following line in "/etc/ssh/sshd_config": GatewayPorts no